dm raid: remove ti_error_* wrappers

There ti_error_* wrappers added very little.  No other DM target has
ever gone to such lengths to wrap setting ti->error.

Also fixes some NULL derefences via rs->ti->error.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2016-05-31 14:26:52 -04:00
commit bd83a4c4f8